There is a long line of work demonstrating that, relative to writing about neutral topics, writing about traumatic experiences produces improvements in physical health. Out of enthusiasm for this line of work, some have suggested that the written disclosure paradigm developed by Dr. James Pennebaker might be used as a therapeutic tool. Although the writing paradigm has been linked to improvements in physical health, relatively little is known about the effects of the paradigm on psychological health. There has also been speculation that males experience greater benefits from the paradigm than females, though no study has directly examined sex differences. Another important issue related to the paradigm relates to the underlying mechanism. While many investigators have studied the paradigm, few studies have examined the mechanism of action. The purpose of the proposed project is to investigate whether written disclosure is associated with improvements in psychological health, in addition to physical health, examine whether sex affects outcome, and if exposure underlies the efficacy of the paradigm. Participants with a history of traumatic experiences will be assigned to either a written emotional disclosure condition or a trivial writing, control condition, For both conditions writing sessions will take place on three consecutive days, for twenty minutes each day. Follow-up visits will take place one month and three months following the writing sessions. Outcome will be evaluated using a both psychological measures and a physical health measure completed at baseline and at the follow-up visits. In addition, both statisticai and clinical significance testing will be conducted. The hypothesis that exposure underlies the effectiveness of the written disclosure paradigm will be examined using self-reported emotion and physiological reactivity to each session. It is expected that the participants assigned to the disclosure condition will show improvement at follow-up compared to participants assigned to the control condition, and that males in the disclosure condition will show greater improvements at follow-up compared females in the same condition. Consistent with an exposure hypothesis, it is expected that disclosure participants will display habituation of emotion (both subjective and physiological) from the first to the last writing session. Further, initial emotional engagement and habituation of emotion is anticipated to be significantly related to symptom improvements at follow-up for the disclosure participants.